package niuke;

/**
 * description:
 * author:zt
 * date:2021-08-02
 */

/**
 * 已知两颗二叉树，将它们合并成一颗二叉树。合并规则是：都存在的结点，就将结点值加起来，否则空的位置就由另一个树的结点来代替
 */
public class NC117 {

    public TreeNode mergeTrees (TreeNode t1, TreeNode t2) {
        // write code here
        if (t1==null) return t2;
        if (t2==null) return t1;

        TreeNode root = new TreeNode(t1.val+t2.val);
        root.left = mergeTrees(t1.left,t2.left);
        root.right = mergeTrees(t1.right,t2.right);

        return root;
    }
}
